

A176764


Smallest power of 4 whose decimal expansion contains n.


10



1, 256, 16384, 4, 256, 16, 1048576, 16384, 4096, 1024, 1099511627776, 1125899906842624, 1180591620717411303424, 262144, 288230376151711744, 16, 17179869184, 1073741824, 4194304, 72057594037927936, 262144, 4722366482869645213696
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OFFSET

1,2


COMMENTS

This is to 4 as A176763 is to 3 and as A030001 is to 2.


LINKS

Table of n, a(n) for n=1..22.


FORMULA

a(n) = MIN{A000302(i) such that n in decimal representation is a substring of A000302(i)}.
a(n) = 4^A062521(n).  Michel Marcus, Sep 30 2014


EXAMPLE

a(1) = 1 because 4^0 = 1 has "1" as a substring (not a proper substring, though).
a(2) = 256 because 4^4 = 256 has "2" as a substring.
a(3) = 16384 because 4^7 = 16384 has "3" as a substring.


CROSSREFS

Cf. A000302, A030001, A176763, A176765A176773.
Sequence in context: A224283 A224206 A238064 * A235964 A206319 A216397
Adjacent sequences: A176761 A176762 A176763 * A176765 A176766 A176767


KEYWORD

base,easy,nonn


AUTHOR

Jonathan Vos Post, Apr 25 2010


EXTENSIONS

Corrected and extended by Sean A. Irvine and Jon E. Schoenfield, May 05 2010


STATUS

approved



